Question: Evaluate the following expression when $x = 1$ and $y = 8$. $3$ $x$ $ + 8$ $y$ $ + 7$
Answer: Substitute $1$ for ${x}$ and $8$ for ${y}$ $ = 3{(1)} + 8{(8)} + 7 $ $ = 3 + 64 + 7 $ $ = 74$